378 APHIDS OF THE ROCKY MOUNTAIN REGION 
Genus Hamamelistes Shimer 
Shimer, 1867:284; Baker, 1920a:83. 
Characters. Antenna rather thick, bearing numerous narrow and annular 
sensoria. Antenna three-segmented in coccidlike hibernating aptera, five-seg- 
mented in summer aptera and alata. Tarsi two-segmented in summer forms 
and bearing a pair of capitate hairs; but in aptera may be abortive or missing. 
Living in leaf galls or as coccidlike forms on twigs and leaves. 
Genotype (one unquestioned species), Hamamelistes spinosus Shimer. 
Genotype Hamamelistes spinosus Shimer 
Hamamelistes spinosus Shimer, 1867:284; Pergande, 1901:25; Gillette and Palmer, 
1934 : 242. 
Apterous Summer Vivipara. Body length 1.6; hind tibia .35; antenna .30; rostrum at- 
taining 2d coxa. 
A few individuals taken at Manitou in June had tarsi abortive especially on 
1st and 2d tibiae. These individuals may belong to the previous generation as 
they appear older. 
Alate Vivipara. Body length 1.5-2; fore wing 2.6-3; hind tibia .45; hind tarsal II .09; 
antenna .65. 
— ce 
UK 
(30) (sen. 27~ Wy (14) (sen.t2-t4) (-10)(senu-t3) 
Fig. 455. Hamamelistes spinosus 
Collections. On leaves of Betula fontinalis (alternate host, Hamamelis sp., 
not taken in region); very rare. Colorado: Manitou and Masonville. Apterous 
summer viviparae June 15 and Aug. 4. (Alate viviparae not taken, described 
and figured from specimens taken in the eastern United States). 
